Filters

2020 - 20212

More filters

20212
Reset filters

Settings

Publisher: Weinheim : WILEY-VCH Verlag ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Key Parameters for the Synthesis of Active and Selective Nanostructured 3d Metal Catalysts Starting from Coordination Compounds – Case Study: Nickel Mediated Reductive Amination
    (Weinheim : WILEY-VCH Verlag, 2021) Klarner, Mara; Blach, Patricia; Wittkämper, Haiko; de Jonge, Niels; Papp, Christian; Kempe, Rhett
    The design of nanostructured catalysts based on earth-abundant metals that mediate important reactions efficiently, selectively and with a broad scope is highly desirable. Unfortunately, the synthesis of such catalysts is poorly understood. We report here on highly active Ni catalysts for the reductive amination of ketones by ammonia employing hydrogen as a reducing agent. The key functions of the Ni-salen precursor complex during catalyst synthesis have been identified: (1) Ni-salen complexes sublime during catalyst synthesis, which allows molecular dispersion of the metal precursor on the support material. (2) The salen ligand forms a nitrogen-doped carbon shell by decomposition, which embeds and stabilizes the Ni nanoparticles on the γ-Al2O3 support. (3) Parameters, such as flow rate of the pyrolysis gas, determine the carbon supply for the embedding process of Ni nanoparticles.
  • Thumbnail Image
    Item
    Development of Highly Stable Low Ni Content Catalyst for Dry Reforming of CH4-Rich Feedstocks
    (Weinheim : WILEY-VCH Verlag, 2020) Ha, Quan Luu Manh; Lund, Henrik; Kreyenschulte, Carsten; Bartling, Stephan; Atia, Hanan; Vuong, Than Huyen; Wohlrab, Sebastian; Armbruster, Udo
    Highly active and coking-resistant Ni catalysts suited for the dry reforming of CH4-rich gases (70 vol %, e. g. biogas or sour natural gas) were prepared starting from a Mg-rich Mg−Al hydrotalcite support precursor. Calcination at 1000 °C yields two phases, MgO and MgAl2O4 spinel. Complexation-deposition of Ni with citric acid on the preformed support as well as lanthanum addition yields a catalyst with remarkably low carbon accumulation over 100 h on stream attributed to both high Ni dispersion and preferred interactions of Ni with MgO on MgAl2O4. © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.